Improvement in annealing-boxes



-c. MGNISH, M Annealing Boxfes.

N0 149 875. y PatentedAprHZLlSM.

Jrwww j f mw Unn'riinV STATES PATENT FFICE,

CHARLES A. MCNISH, 0F PITTSBURG, PENNSYLVANIA.A

*IMPROVEMENT` IN ANNEALlNG-BOXES.

Specification forming part of Letters Patent No. 149,875, dated April 21, 1874 application filed v March 17, 1874.

To all whom 'it may concern:

Be it known that I, CHARLES A. MONISH,

of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Annealing-Boxes 5 and I do hereby declare the following to be a Heretofore these articles have been madeby` casting 5 but, on account of their own weight and the extreme weight of the `pack of sheet-iron placed in them, and of the cover or lid, and on account of the intense heat to which they are exposed, such boxes have, as a general thing, lasted about two weeks, being used only for about four heats. The effect of the great wei ght and of the variations of temperature upon the granular structure of the cast-iron fractures it and causes the boxes to break. I have dis,

covered by actual experience that by forming ribs of wrought-iron, or other like metal, in the sides and bottom, as indicated at a in the drawing, the bottom A is greatly strengthened, and rendered very much less liable to break, and that if the cast portions of the same do fracture the whole is heid together by the more elastic ribs a.

The method of forming these ribs is by placing bars of wrought-iron in the mold in suitable cavities, or by placing them just above the flat bottom of the mold, so that when the castiron is poured in it will flow around them and form the ribs a, or incorporate the rods a in the sides of the bottom itself without forming ribs thereon. These bottoms do not rest directly on the oor of the oven, but on rollers or balls, which fit in the circular grooves c, and which are for the purpose of running the boxes in or out ofthe ovens.

It has been my experience that by this means I am enabled to use an inferior quality of metal for casting these boxes, and that instead of their lasting but two weeks, as when made 4entirely of cast-iron, they last for several months.

lVhat I claim as my invention, and desire to secure by Letters Patent, is-

A bottom for annealingboxes having ribs or. bars of wrought-iron, or other metal of a similar fibrous elastic nature, extending through it, substantially as described.

In testimony whereof I, the said CHARLES A. MCNISH, have hereunto set my hand.

enfAs. A. Mauren.

litnesses T. B. KEER, J AMES I. KAY. 

